Holder for thermionic tubes



.1948- G. WAGSTAFF I 2,455,324

HOLDER FOR THERMIONIC TUBES Filed Oct. 14, 1943 Inven Z 0?": George Patented Nov. 30, 1948 HOLDER FOR THERMION- C ,i'EUBES George Wagstafi, Long Eaton,

England, assignor to United-Carr Fastener Corporation, Cambridge, Mass, a corporation of Massachusetts Application October 14, 1943, Serial No. 506,295 In Great Britain October 14, 1942 2 Claims.

The present invention relates to holders for thermionic valves and other electrical devices and more particularly to contacts therefor adapted to screen the other pin-receiving contacts of the holder.

It has been the usual practice to provide a central screening contact comprising a one-piece tube inserted in a central aperture in the holder, the tube being held in place by flanges which extend over the face of the holder towards the pinreceiving contacts.

According to the present invention the screening contact comprises two tubular or like parts having shoulders or projections for engaging opposite faces of a flange or the like in a central aperture in the base of the holder, the two parts having interengaging means for securing them together when in assembled position.

To enable the invention to be fully understood it will now be described with reference to the accompanying drawings, in which:

Fig. l is a central sectional elevation of a holder having a screening contact according to one embodiment of the invention, and

Fig. 2 is a plan view of Fig. 1.

As shown in the accompanying drawings the holder I is of the solid moulded type made of ceramic or like material and. is mounted in an attaching plate 2. The holder has the usual apertures 3 for the pin-receiving contacts 4 and a central aperture 5 of larger diameter than the apertures 3. An annular flange or shoulder 6 is provided in the aperture adjacent to the lower face of the holder, the shoulder defining an aperture 'I'. The central screening contact which is inserted in the aperture 5 consists of two complementary parts one comprising a tubular metal sleeve 8 having an inturned flange 9 and an outturned flange Ill.

The other part comprises a tubular sleeve I I having a reduced end portion forming a neck I2.

The sleeve 8 is inserted into the aperture 5 from the upper face of the holder, the dimension of the sleeve being such that the flange 9 rests on one face of the shoulder I5 and the flange I rests on the upper face of the holder.

The sleeve I I is inserted in the aperture from the underface of the holder, the neck portion I2 extending through the aperture defined by the flange 9 and the end I3 of the sleeve I I resting on the underface of the shoulder B. The end of the neck is then headed over by a suitable tool to secure the two sleeves 8 and II together.

One or both sleeves may comprise seamless drawn tubes or they may be formed by bending a flat sheet metal blank into cylindrical form.

It will be understood that the two parts may take other forms than that described above and may be secured together by any convenient means for example by a cooperating snap fastener action, or screw threads. A wiring tag or aperture I It is preferably provided on the sleeve I I to facilitate connection with an earthed lead.

Although the two-piece contact is particularly applicable for solid moulded holders it may be used for other types of holders if desired.

It will be understood that if desired the sleeve 8 may be formed with a reduced neck portion and the sleeve II formed with an inwardly extending flange over which the neck is headed to secure the sleeves together.

What I claim is:

1. A holder for thermionic and like valves comprising a body of insulating material provided with an annular series of prong-engaging contacts and a central bore extending therethrough and provided with an inwardly extending annular rim intermediate its ends presenting axially spaced opposed shoulders and a reduced prongreceiving bore, a two-part screening contact mounted in said bore on opposite sides of said rim and comprising a female member having a flange engaging a face of said body and an apertured base engaging one of said shoulders and a male member having a flanged base bearing against an opposite shoulder and a tubular prongreceiving portion extended through said reduced bore and the apertured base of said female member, the terminal end of said tubular prong-receiving portion being interengaged with the apertured base of said female member to hold said screening contact parts in assembled relation and in engagement with said opposed shoulder of said central bore.

2. A holder for thermionic and like valves comprising a body of insulating material provided with an annular series of prong-engaging contacts and a central bore extending therethrough and provided with an inwardly extending annular rim intermediate its ends presenting axially spaced opposed shoulders and a reduced prongreceiving bore, a two-part screening contact mounted in said bore on opposite sides of said rim and comprising a female member having a flange engaging a face of said body and an apertured base engaging one of said shoulders and a male member having a flanged base bearing against an opposite shoulder and a tubular prongreceiving portion extended through said reduced bore and the apertured base of said female member, the terminal end of said tubular prong-receiving portion being upset over the apertured base of said female member to hold said screening contact parts in assembled relation and in engagement with said opposed shoulder of said central bore.

GEORGE WAGSTAFF.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 

